The world's #1 resource for everything Subaru Tecnica International, with a core focus on supporting every individual in a positive environment, regardless of experience and technical ability.
Please take a second to click here to register, and in a few simple steps you will be able to enjoy a "NO DRAMA" community. Once registered please introduce yourself.
Thank You.

IGOTASTi is an online forum and community for all Subaru WRX STi enthusiasts. In the forum you will find an informative tech area, a place for Member’s journals, Vendors with special Members pricing, and monthly contests.
If this is your first visit, be sure to
check out the helpful FAQ and click REGISTER to sign up.

PLEASE NOTE: SECURITY SPAM FEATURE

Our system prevents potential spam from registering and ruining your experience in our forum. Sometimes it may prevent a true user from registering. If this happens to you please contact us at info@igotasti.com with your preferred user name & email address and we will create your account for you. We will send you a welcome letter with your user conformation to the email you provide us, if you don't receive it please check your spam folder in your email account. Thank you.

User Info Menu

Join Date

May 2019

Posts

5

Local Date

05-25-2019

Local Time

09:04 AM

Subie newbie from MD

Hey everyone. Knew to the go fast car scene. Rode motorcycles for a few years then my son came along and I decided to ditch that life for now and get a fun car so I bought a 2018 STI. Trying to learn as much as I can here. Currently stock running the stage 1 tune from Cobb. Plan on doing an intake and maybe some exhaust work and then looking to get it pro tuned. Suggestions on who to look into and what else I can do to make this car reliable would be great. Oh also I have a mishimoto catch can installed and eventually plan on getting the iag aos to replace that.

Re: Subie newbie from MD

Welcome! You've come to the right place. There is lots of information here and a ton of good people that will point you in the right direction.

A catch can or AOS is a great modification for reliability's sake, though they are not quite as necessary on a stock engine as they are on a built engine.

Everyone likes to open up the intake for the increased turbo spooling and bypass valve noises. Most off the shelf tunes (such as Cobb) are not optimized for an aftermarket intake and changing the intake often has a greater than expected effect on engine health due to changes in the way the MAF is reading. Worst case scenario, an intake causes you to run lean, knock and have catastrophic piston damage. Plus, the stock intake is very capable up to around 400whp. Either way, if you must change the intake, you should definitely get a protune.

If you just want the increased turbo sounds, I would suggest removing the intake silencer. This will not effect the tune.

The "Stage II" level of modifications is probably the most common/popular with these cars. At a basic level, it requires a new downpipe and a tune. There are lots of different opinions on what downpipe (or full turboback, that is a downpipe + catback) is best. But first we have to discuss what your lifetime plans are for this car.

If you don't plan on much beyond ~325whp, then a Stage II level is fine. If you foresee wanting more in the future, then I generally recommend a turboback exhaust, upgraded fuel pump, larger injectors, turbo inlet, intake and protune. This can all get expensive really fast, so make sure you have done your homework and drawn up a plan. No one likes to spend extra money to re-do something you modified previously.

User Info Menu

Car

2007 STI OBP

Join Date

Aug 2011

Location

DC

Posts

4,050

Local Date

05-25-2019

Local Time

10:04 AM

Awards

Re: Subie newbie from MD

Mirroring the above,

Research! And then post, then research some more!

If you know your ultimate goals, you can do some incremental things along the way, but it always stinks to have to replace something you already bought that isnt up to the task later (fuel pump, injectors, etc...).

I'd also strongly recommend looking into a few handling tweaks such as swaybars and endlinks.

And then dont forget about looks! Front lips, difusers, tints, lowering (although definitely do research on this first, or ask questions...or both), new/wider rims, etc...

User Info Menu

Re: Subie newbie from MD

Welcome to IGOTASTI!! You're going to absolutely love it here!! Post some pictures of the ride!!

What other cars have you had in the past? How does the STi compare to them? Is there anything you don't like about it? What do you love about it?

What motorcycles have you had? Do you have any pictures of them? (My last one was an '07 CBR 600RR.)

The very first thing that you should've done was read the owner's manual! If you already read it, read it again! The second thing you should be doing, whenever you're not driving, is reading and researching! (Both of these are completely and truly free, and you ONLY have positives to gain from them!) The best bang for the buck is what we call the "driver mod." You need to get accustomed being behind the wheel and learn how the car behaves. You will be the most important aspect of how your car performs!

Next, and this is extremely important, ask ANY AND ALL questions you may have! It's entirely beneficial in your favor to ask before you act! Learning from other people's mistakes is free and a crucial impact on your journey! This is the only Subie forum that I'm on anymore and there is a major reason for that: there is no misinformation on here! If we truly don't know the answer to something, we will point you in the right direction where someone else can help who actually knows!

I also recommend you start a member's journal. You can brainstorm what you want to do before you actually do it and we'll help you along the way so you avoid as many mistakes as possible.

Also, to add to what @Grinder34 and @Batmobile_Engage have said, don't overlook tires! They are the only thing between you and the road! Save the money you would spend (or rather essentially waste) on an intake and put it towards something else that will have a bigger and more meaningful impact.

User Info Menu

Join Date

May 2019

Posts

5

Local Date

05-25-2019

Local Time

09:04 AM

Re: Subie newbie from MD

Thanks everyone for the advice! What are the best parameters to monitor on the AP and what are normal values I should be seeing on stage 1 Cobb tune. I’ve been trying to search around on forums for the answers but a lot of threads seem to jump around a lot and it’s hard to follow what is actually being said.

(If I recall correctly, the AP always measures the AFR (air to fuel ratio) correctly no matter what. This is the reason why a dedicated wideband/AFR sensor/gauge is required for tuning and also to monitor the correct ratio.)

User Info Menu

Car

2015 WRX STi Limited GBP

Join Date

Sep 2011

Location

PA

Posts

649

Local Date

05-25-2019

Local Time

10:04 AM

Awards

Re: Subie newbie from MD

Originally Posted by Ace

Thanks everyone for the advice! What are the best parameters to monitor on the AP and what are normal values I should be seeing on stage 1 Cobb tune. I’ve been trying to search around on forums for the answers but a lot of threads seem to jump around a lot and it’s hard to follow what is actually being said.

Sent from my iPhone using Tapatalk

This is why we encourage questions here. Who cares if it has been asked before. If we have a really good master thread on something we will point you toward it, otherwise, ask away.

With that out of the way, welcome! I echo what others have said so far. Skip the intake for now unless you reallllly want more whooooshy sounds. If that is the case go with the Cobb intake that way you can run the stage 1 + tune from them until you get protuned later. Yes every car is different and therefore benefit from individual tuning, but Cobb does extensive testing for their maps and if you follow their mods specifically, you can run their OTS maps. Sure you will make less power than you could with a protune, but you will be safe until getting a more specialized tune.

As others said, look at the suspension, exterior bits, wheels/tires, shifter, etc. Some of those mods are significantly cheaper than performance mods while making the car substantially more fun to drive. I'm personally Cobb stage 1 on my 15 STi with Whiteline and Super Pro suspension, short shifter, Enkei wheels & summer tires, muffler deletes, and a few exterior parts. It has all added up to a car that I love driving, hearing, and staring at as I walk away. Just the sounds and looks make me smile with this car. I had a built 06, it was fun as hell. But honestly this car has been more enjoyable so far.

(If I recall correctly, the AP always measures the AFR (air to fuel ratio) correctly no matter what. This is the reason why a dedicated wideband/AFR sensor/gauge is required for tuning and also to monitor the correct ratio.)

I'm sure someone else will correct me if needed and also chime in.

What kind of information is the fuel trims giving me and what should I be looking for?

User Info Menu

Re: Subie newbie from MD

Welcome to IGOTASTI!! You're going to absolutely love it here!! Post some pictures of the ride!!

What other cars have you had in the past? How does the STi compare to them? Is there anything you don't like about it? What do you love about it?

What motorcycles have you had? Do you have any pictures of them? (My last one was an '07 CBR 600RR.)

The very first thing that you should've done was read the owner's manual! If you already read it, read it again! The second thing you should be doing, whenever you're not driving, is reading and researching! (Both of these are completely and truly free, and you ONLY have positives to gain from them!) The best bang for the buck is what we call the "driver mod." You need to get accustomed being behind the wheel and learn how the car behaves. You will be the most important aspect of how your car performs!

Next, and this is extremely important, ask ANY AND ALL questions you may have! It's entirely beneficial in your favor to ask before you act! Learning from other people's mistakes is free and a crucial impact on your journey! This is the only Subie forum that I'm on anymore and there is a major reason for that: there is no misinformation on here! If we truly don't know the answer to something, we will point you in the right direction where someone else can help who actually knows!

I also recommend you start a member's journal. You can brainstorm what you want to do before you actually do it and we'll help you along the way so you avoid as many mistakes as possible.

Also, to add to what @Grinder34 and @Batmobile_Engage have said, don't overlook tires! They are the only thing between you and the road! Save the money you would spend (or rather essentially waste) on an intake and put it towards something else that will have a bigger and more meaningful impact.

I love the car as a whole fun to drive decent gas mileage. I just wish I could actually hear the turbo and exhaust was a bit louder. Oh and the stock radio sucks wish the 2018 had apple play. Also rev hang on stock tune was terrible.